Corrosion inhibition and corrosion inhibited hydrocarbon



CORROSION INHIBITION AND CORROSION INHIBITED HYDROCARBON Thomas 0. Counts, Park Forest, 11]., assignor to Sinclair Refining Company, New York, N.Y., a corporation of Maine No Drawing. Filed Apr. 15, 1957,.Ser. No. 652,675

25 Claims. (Cl. 2528.55)

My invention relates to the inhibition of corrosion, particularly the corrosion of iron and steel when in contact with petroleum hydrocarbons.

It is well known that rust frequently occurs in pipe lines, storage tanks and other equipment because'of arate liquid phase beneath the main body of gasoline.v

Water can also enter gasoline systems along with air through partially filled tanks provided with breather devices.- As such a tank cools, for example, at night, its contents contract and moisture-laden air is drawn in. This moisture condenses on the walls of the tanks, settles to the bottom and dried air is expelled when the contents of the tank again warm up, as from the heat of the sun the next day. Repetition of this cycle eventually leaves an appreciable amount of moisture at the bottom of the tank;

Rust that forms permanently injures expensive equipment and there is additional loss in terms of replacement costs of such equipment and operating time lost during such replacement. For example, where rust forms on interior surfaces of product pipe lines which are used for the transportation of light petroleum distillates such as gasoline, kerosene and home heating oil, and no efiort is made to prevent the rust, this formation of rust can reduce the carrying capacity of the lines by more than 12 percent in one year. In addition to the decrease in life of rusted equipment such as storage tanks, there is also the danger of trouble in engine operation from failure of fuel carrying equipment and the likelihood of rust particles clogging carburetors or injecting devices for motors and burners, for example.

Another area in which iron and steel are subjected to corrosion is in the production of petroleum from wells. Some degree of corrosion takes place in the metallic equipment of practically all oil wells and in certain environments corrosion reaches costly proportions. The casing, tubing, sucker rods, and lead lines are particularly subject to corrosive effects. The sucker rods and sucker rod boxes which operate under heavy cyclic load conditions are especially susceptible to failure through corrosion fatigue. As a result of corrosion, co's'tsmay be greatly increased because of the necessity of. pulling tubing and sucker rods for repair or replacement. Indirectcosts'in terms of production losses dur- Part of this dissolved moisture sep:

ing shut-down for repair or replacement of rods, tubing and other equipment can also prove to be considerable.

In accordance with my invention, I have discovered that the corrosion of iron and steel which normally takes place when iron and steel are in contact with a petroleum hydrocarbon can be prevented or substantially retarded or inhibited by including in the petroleum hy drocarbon a small amount of an ammonium or aminesalt RCH(SO OH)COOH, where R is an alkyl group having from 6 to 20 carbon atoms, and preferably from 14 to 18 carbon atoms. Mixtures of such salts can also be employed in accordance with my invention. Alphasulfoalkyl acids can be obtained by the sulfonation with sulfur trioxide of the corresponding carboxylic acids in accordance with procedures which are known in the art. Among the alpha-sulfoalkyl acids which can be thus prepared are: alpha-sulfodecanoic acid, alpha-sulfolauric acid, alpha-sulfomyristic acid and alpha-sulfopalmitic acid, alpha-sulfostearic acid and alpha-sulfobehenic acid. The salts which are utilized as corrosion inhibitors in accordance with my invention can be prepared in the way in which salts are normally prepared in the art by reaction of ammonia or an amine and an acid. It will be noted that the alpha-sulfoalkyl acids described above are dibasic acids. With ammonia or an amine, neutralization occurs first at the sulfonic acid group, which is the stronger acid group, and subsequently at the car'- in preparing the alpha-sulfoalkyl acid salts which I use as corrosion inhibitors. Thus, the amines can be primary, secondary or tertiary. The amines can be derived from animal or vegetable fats and oils or rosin. Aromatic and other ring compounds containing a nitrogen atom capable of reacting with an acid can also be employed in. preparing the corrosion inhibitors. Likewise, heterocyclic compounds containing nitrogen such as morpholine or pyridine, are useful, as are polyamines.

Suitable amines for use in preparing the corrosion inhibitors include:

Primary amines: methylamine, isopropyl amine, Z-amino-butane, tertiary butyl amine, 2-amino-4-methylpentane, various amyl, hexyl, heptyl, octyl and higher homologous primary amines Where the amine group is attached to a secondary or tertiary carbon atom; cyclopentyl amine, alkylated cyclopentyl amines, cyclohexyl amine, mono-methyl cyclohexylamines, dImethyl cyclohexylamines, trimethyl cyclohexylamines, other alkylated cyclohexylamines, bornyl amine, fenchyl amine, cycloterpenyl amines, pinyl amine, benzylamine, betaphenyL ethylamine, alkylated benzylamine, tetrahydro betanaphthylamine, allyl amine, beta-methyl allylamine, betachloroallylamine, and their homologs and analogs.

Secondary amines: di-methyl-, di-ethyl-, di-n-propyl-, di-isopropyl-, di-butyl-amines; various secondary amines derived from amyl, hexyl, heptyl, octyl, and higher.

homologous alkyl groups; methyl isobutyl amines,

amine, N-alkyl N-bornyl amine,

1C6 Patented Dec. 27, 1960 of an alpha-sulfoalkyl acid of the formula- N-methyl N-cycloterpenyl amine, N-isopropyl N-(1)- methyl amine, N-alkyl N-benzl amines and their homologs and analogs; dicyclopentyl amine, dicyclohexyl amine, alkylated dicyclohexyl amines; dibenzylamine,

di-(beta phenyl ethyl) amine; piperidine, piperazlne, 5 0.1 mole alpha-sulfopalmitic acid (34.0 g.). The reacalkylated piperidines or piperazines; alkylated and untion was carried out in the same equipment as above. alkylated oxazines such as morpholine and 2,4,4,6-tetra- An excess (5 g.) of amine was added to insure complete methyl tetrahydro-l,3-oxadazine; alkylated 1,3-thiazo1ines reaction. The mixture was heated under vacuum to resuch as 2,4,4,6-tetramethyl tetrahydro-3-thfaz0line. move the excess. The resulting product is a clear, straw- Secondary amine type derivatives of alkylene diamines colored, very viscous mass. It is soluble in benzene. such as: Table I sets forth the names and characteristics of other salts which have been prepared and which are use- 1 2- a ful corrosion inhibitors in accordance with my invention. wherein R and R may be like or different aliphatic, ali-. T bl I cyclic, aralkyl, alkarylalkyl, heterocyclic, terpenic radicals,.and wherein R is an alkylene or cycloalkylene radi- Percent, cal. These R .and R radicals for instance, may be hy- Co po a tive e ark drogen, isopropanyl, butyl, cyclohexyl, benzyl, and/or 5 bornyl radicals. The R radical is preferably an eth- Ylene, P PY tetramethylene radical- Di-morphollne alphasulloste- 90 White powder. Soluble in Tertiary ammes: trimethylamine triethylamine tri-ntime benzene mixture- Water soluble. P py p py tnbutylamlne, g Mono-morpholine alphasul- 80 Clear yellow jelly. Solhomologous and isomeric trialkylamines, variously N- Steam acld- 111218 almholbemene mixture, water soluble. substituted ternary ammes having different organic radi- Mono-ammonium alpha-sul- 1 9 Water soluble (cloudy). cals on the amino nitrogen atom, e.g., alkyl alicyclic, fonalmltic acids b bornyl, fenchyl, aralkyl, and like homologs and analogs; slfilksieafi iclfi alphaF 100 gafi l l lb l lieiil b l l r and tertiary amine type derivatives of alkylene diamines. 9 mixtllm C d l The precise amount of the alpha-sulfoalkyl acid salt wg i if lspersion n admixed with the petroleum hydrocarbon will depend g ggiggfggg g ggg g g fg mwenbemene' upon the particular petroleum hydrocarbon and also up- Dimethyl hydro' enated an- 100 Tan solid. Insoluble in, on other-factors. Generally, however, the amount of g i ki g gfg s salt employed as the corrosion inhibitor will be within Methyl-di-hydrozenated tal- 100, Hard, waxy,tan solid. Inthe range from 0.25 to 25 pounds per 1000 barrels of igfigg g g alpha suuopal' $11,2 3 $2, 22, 55 the petroleum hydrocarbon. Where the petroleum hy- Dl-(di-Z-ethyl hexyl amine) 100 Clear, dark red-brown visdrocarbon is a petroleum distillatehaving a viscosity not alpha Sumpalmitate m exceeding that of gas oil, such as gasoline, kerosene and Mono (d1 2 ethyl hexyl 78 Clear, dark, red-brown llq-. home heating oil, the amount of salt used as the corro- 35, 5??? ialpha'sulfopalmitic gli;, ggfigi g lffi, f sion inhibitor will preferably be within the range from 40 0.25 to 5 pounds per 1000 barrels. On the other hand, Balanceisisomomnoh when the salt is used as a corrosion inhibitor in an oil Well, the amount of salt utilized will preferably be within fig g g i gsg z gg 3x223 3 Each of the eleven salts described above'was-testedthe crude y 1 for effectiveness in inhibiting corrosion by a modified The followin exam le illustrates various embodiments ASTM D465 turbine on rust test Procedure A for diswhich fall witgin thepsco e of m invention tilled water was used, but the test was shortened to four.

p y hours and the temperature of the test was reduced to 100 F. Thus, a freshly ground rust test coupon con-:- EXAMPLE sisting of a /2 inch diameter'by 5 inches long mild In order to prepare mono-(di-butylamine) alpha-sulfostfiiel rod suspended a 400 breaker equlpped: with a stirrer and placed in a temperature control bath palmrtic acid, 0.05 gram mole of alpha-sulfopalmitlc acid o o I capable of maintaining the termperature at 100 R11 F. was weighed 1nto a beaker equipped with a stirrer and I The gasoline or diesel fuel to be tested (350 ml.) was a thermometer. About 20 grams of 1sopropanol-benzene add d and sfned for 30 minutps ywlfle containin thefl (75-25 volume ratio) mixture was used as a solvent-for rusteinh.b.tor recoat the test Part (sogml the acid. To hasten solution, the mixture'was heated to f the g (1.686} fuel s; then r'emoved and about 100 F. with stirring, until all ofthe acid had been 0 of (istinled i was added and the mixmr fir ed dissolved. The solution was then'allowed to cool to 1 r for 3 hours. At the end of this time, the coupon was room temperature.

removed, dried with solvents, inspected andv rated ac-- 0.05 gram mole of di-butylaminem a separate beaker cording to the'following taole; was poured slowly with sttrring into the acid solution wh ch was placed in a cold water bath. Addition of the Rating: Percent of surface rusted amine took about 30 seconds. The temperature was not A None allowed to rise over about 120 F., being controlled by B+.+ 0 to 0.25 the use of the bath. The reaction was essentially com- B+ 0 25 to 5 plete after about 10 minutes of stirring. A brown solid 25 mass which was soluble in benzene and soluble in iso- C 25 to propanol was obtained after the solvent was stripped D 50 to 5 off using a vacuum. a 'I 7 H V I V to 1001 The di-salts, in which both thevsulfonic acid group of the acid and amine (liquid) without using a solvent.

An example of this is as follows:

Di-(di-n-butylamine) alpha-sulfopalmitate was prepared by adding 0.2 mole (25.8 g.) di-n-butylamine to ""L. It

and carboxyl group are neutralized canbe prepared in Table 11 sets forth the minimum ,concentration of; an analogous manner. Often, it is possible to prepare ammonium or arnine salt in points per1000 barrels 05,." di salts of '100percent active ingredient by direct gasoline or diesel fuel required ,to ,give a B-fl-rl-vrating amass in the test. J Table II alsosets forth comparative results obtained with various commercial corrosion inhibitors.

Table 1! Minimum Concentration, #/l.000 Bbls. for B++ Inhibitor Ratings Gasoline Diesel Fuel A. Mono-salts:

Morpholine alpha-sultostearie acid 0. 75 0. 75 Ammonium alpha-sulfopalmitic acid 0. 75 0. 75 N-tallow morpholine alpha-suliostearic acid... 0. 75 1 Mono-(dimethyl hydro enated tallow amine) alpha-sulfonalmitic acid 4.5 2.25 (Methyl dihydrwenated tallow amine) alpha-sultopalmitic acid 0. 4 2. 25 N'at n inopropyl morpholine alpha-suli'ostearic 3. 75 0. 4

Mong-(di-n-butylamine) alpha-sultopalmitic 0. 4 1. 5

an Monoi-Q-ethyl hexylamine) alpha-suliopal- 0.75 2. 25

mitic acid 2B. Di-Salts: 2 1

Di-morpholine alpha-suliostearate Di-(di-2-ethylhexyl amine) alpha sultopal- 1 2 mitate 0. 5 2 Di-(di-n-hurylamine) alpha-sulfopa1mitate.. 0. Commercial Inhibitors 20 12 A (10% active ingredient)- g g 8 6 4 ll 1 100% active ingredient basis. 1 As received basis.

When the ammonium or amine salts of the alpha-sulfoalkyl acids are utilized as corrosion inhibitors for the purpose of preventing corrosion in oil wells, the inhibitor is added to the well fluids by conventional methods, usually by merely injecting the desired amount of inhibitor down the annulus between the production tubing and the casing. The resulting crude produced from the well, after separation of any brine by conventional methods, displays favorable corrosion inhibiting properties when transported through connecting pipe lines to the refinery.

I claim:

1. A method for prevention of the corrosion of iron and steel in contact with a liquid petroleum hydrocarbon containing moisture which comprises admixing with the petroleum hydrocarbon an amount efiective to substantially inhibit the corrosion of a salt of an acid of the formula RCH(SO OH)COOH, the said salt being selected from the group consisting of ammonium and amine salts, the said salt being selected from the group consisting of those in which only the sulfonic acid group has been neutralized and those in which both the sulfonic acid group and the carboxyl group have been neutralized, R being an alkyl radical containing from 6 to 20 carbon atoms.

2. The method of claim 1 wherein the amount of said salt is within the range from 0.25 to 25 pounds per 1000 barrels of said liquid petroleum hydrocarbon.

3. The method of claim 1 wherein said liquid petroleum hydrocarbon is a petroleum distillate having a viscosity not exceeding that of gas oil.

4. A method for the prevention of the corrosion of iron and steel in contact with gasoline containing moisture which comprises admixing with the gasoline from 0.25 to 5 pounds per 1000 barrels of gasoline of a salt of an acid of the formula RCH(SO OH)COOH, the said salt being selected from the group consisting of ammonium and amine salts, the said salt being selected from the group consisting of those in which only the sulfonic acid group has been neutralized and those in which both the sulfonic acid group and the carboxyl group have been neutralized, R being an alkyl radical containing from 6 to 20 carbon atoms.

The method of claim 4 wherein saidsalt is ainmonium alpha-sulfopalmitic acid.

' 6. The method of claim 4 wherein said salt is (methyl dihydrogenated tallow amine) alpha-sult'opalmitic acid.

7. The method of claim 4 wherein said salt is mono-(din-butylamine) alpha-sulfopalmitic acid.

8. The method of claim 4 wherein said salt is mono- (di-2-ethyl hexylamine) alpha-sulfopalmitic acid.

9. The method of claim 4 wherein said salt is di-(di-nbutyl amine) alpha-sulfopalmitate.

10. A liquid petroleum hydrocarbon containing moisture having admixed therewith an amount effective to substantially inhibit the corrosion of iron and steel of a salt of an acid of the formula RCH(SO OH)COOH, the said salt being selected from the group consisting of ammonium and amine salts, the said salt being selected from the group consisting of those in which only the sulfonic acid group has been neutralized and those in which both the sulfonic acid group and the carboxyl group have been neutralized, R being an alkyl radical containing from 6 to 20 carbon atoms.

11. The liquid petroleum hydrocarbon composition of claim 10 wherein the amount of said salt is within the range from 0.25 to 25 pounds per 1000 barrels of said liquid petroleum hydrocarbon.

12. The liquid petroleum hydrocarbon composition of claim 10 wherein said liquid petroleum hydrocarbon is a petroleum distillate having a viscosity not exceeding that of gas oil.

13. Gasoline containing moisture having admixed therewith as a corrosion inhibitor from 0.25 to 5 pounds per 1000 barrels of gasoline of a salt of an acid of the formula RCH(SO OH)COOH, the said salt being selected from the group consisting of ammonium and amine salts, the said salt being selected from the group consisting of those in which only the sulfonic acid group has been neutralized and those in which both the sulfonic acid group and the carboxyl group have been neutralized, R being an alkyl radical containing from 6 to 20 carbon atoms.

14. The gasoline composition of claim 13 wherein said salt is ammonium alpha-sulfopalmitic acid.

15. The gasoline composition of claim 13 wherein said salt is (methyl dihydrogenated tallow amine) alpha-sulfopalmitic acid.

16. The gasoline composition of claim 13 wherein said salt is mono-(di-n-butylamine) alpha-sulfopalmitic acid.

17. The gasoline composition of claim 13 wherein said salt is mono-(di-Z-ethyl hexylamine) alpha-sulfopalmitic acid.

18. The gasoline composition of claim 13 wherein said salt is di-(di-n-butyl amine) alpha-sulfopalmitate.

19. In the production of oil from wells wherein a stream of well fluid is withdrawn from an oil well in contact with iron or steel surfaces, the method of reducing the corrosive efiect of said well fluid upon the iron or steel surfaces which comprises introducing into the stream of well fluid an amount effective to substantially inhibit said corrosive eflect of a salt of an acid of the formula RCH(SO- OH)COOH, the said salt being selected from the group consisting of ammonium and amine salts, the said salt being selected from the group consisting of those in which only the sulfonic acid group has been neutralized and those in which both the sulfonic acid group and the carboxyl group have been neutralized, R being an alkyl radical containing from 6 to 20 carbon atoms.

20. The method of claim 19 wherein the amount of said salt is within the range from 1 to 25 pounds per 1000 barrels of said well fluid.

21. The method of claim 20 wherein said salt is am monium alpha-sulfopalmitic acid.

22. The method of claim 20 wherein said salt is (methyl dihydrogenated tallow amine) alpha-sulfopalmitic acid.

23. The method of claim 20 wherein said salt is mono- (di-n-butylamine) alpha-sulfopalmitic acid.

References Cited in the file of this patent,

UNITED STATES PATENTS Kalischer etal; Dec; 8, 1 93-1 Cnvell Sept; 20, 1932 Guntheret' a1 Sept; 12, 1933 DeGroote et a1 J ul'y 17, 1934 Smith Sept. 5, 1944' Watkins, .I Dec. 12, 1950'. Wachter etal. Jan. 2 2,, 1952.

Watkins Mar. 24, 1953 Jones ..Z.' July 24, 1956 FOREIGN PATENTS Great Britain Sept. 21, 1928 OTHER REFERENCES Weil et alz: Synthetic Detergents From Animal Fats, article in the Jour. of Amer. 0i] Chem. 800., March 1957, vol. XXXIV, No. 3, pages 100-103. 

10. A LIQUID PETROLEUM HYDROCARBON CONTAINING MOISTURE HAVING ADMIXED THEREWITH AN AMOUNT EFFECTIVE TO SUBSTANTIALLY INHIBIT THE CORROSION OF IRON AND STEEL OF A SALT OF AN ACID OF THE FORMULA RCH(SO2OH)COOH, THE SAID SALT BEING SELECTED FROM THE GROUP CONSISTING OF AMMONIUM AND AMINE SALTS, THE SAID BEING SELECTED FROM THE GROUP CONSISTING OF THOSE IN WHICH ONLY THE SULFONIC ACID GROUP HAS BEEN NEUTRALIZED AND THOSE IN WHICH BOTH THE SULFONIC ACID GROUP AND THE CARBOXYL GROUP HAVE BEEN NEUTRALIZED, R BEING AN ALKYL RADICAL CONTAINING FROM 6 TO 20 CARBON ATOMS. 